Overlap between autism and specific language impairment: comparison of Autism Diagnostic Interview and Autism Diagnostic Observation Schedule scores.

Autism and specific language impairment (SLI) are developmental disorders that, although distinct by definition, have in common some features of both language and social behavior. The goal of this study was to further explore the extent to which specific clinical features of autism are seen in SLI. The children with the two disorders, matched for non-verbal IQ, were compared on the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS). In the SLI group, 41% met autism or autism spectrum cut-offs for social or communication domains either on the ADI or ADOS or both. No relationship was found between the language deficits exhibited by the children with SLI and their scores on the ADI and ADOS. These findings contribute to evidence that there is some overlap in social and communicative deficits between autism and SLI, supporting the view that autism and SLI share etiologic factors. This continuum of pathology between SLI and autism appears to range from structural language abnormalities as seen in individuals with SLI to individuals with SLI with both structural and social abnormalities to individuals with autism with pragmatic impairment and language abnormalities.